at the start when you first joined the RAD exchange program, Mammon thought he'd never like a human like you. Heck, he told himself he'd let Lucifer beat him up over getting caught acting all buddy-buddy with the human...

but overtime, he's grown fond of you. He might even love you more than his credit card, Goldie, but that's besides the point... students at RAD talk about how you and Mammon look good together... and he's seemingly internally agreeing with that